Retarget branch in Pull Request not taking effect

[Sean Markus]

I have a PR that I need to update the target branch in. I click the current target branch, then in the Branch dropdown, choose the new target branch, then click the checkmark. This pops a confirmation that the pull request was officially retargeted:

But even after clearing cache and refreshing the page, the target is still the same. 

How can I retarget the Pull Request? I guess I could decline and make the Pull Request again, but I have a lot of these and don't want to do this for each.

[Sean Markus · Accepted solution]

I figured it out, there was already a Pull Request for this branch to branch merge open. The success message is a bit misleading, but I suppose it's on me for not seeing this.